#include <bits/stdc++.h>
using namespace std;
 
int main()
{
	int Aw, Ab, Bw, Bb, C, D;
	cin >> Aw >> Ab >> Bw >> Bb >> C >> D;

	int b = min( C, Ab );
	Ab -= b;
	Bb += b;
	int w = C - b;
	Aw -= w;
	Bw += w;
	w = min( D, Bw );
	Bw -= w;
	Aw += w;
	b = D - w;
	Bb -= b;
	Ab -= b;

	cout << Aw << endl;
}